Automatic fleet angle compensation apparatus



1964 F. L. LE Bus, sR.. ETAL- AUTOMATIC FLEET ANGLE CQMPENSATION APPARATUS 2 Sheets-Sheet 3 Filed Dec. 8, 1961 INVENTORS F. L. Le Bus 55 Fe nold 5 5021297.

ACrow/e ATTORNEY M Feb. 25, 1964 F. L. LE BUS, 5a.. ETAL AUTOMATIC FLEET ANGLE COMPENSATION APPARATUS 2 Sheets-Sheet 2 Filed Dec. 8, 1961 :DIRECf/G/V OF PULL CENTER LINE OF SHAFT INVENTOR. ,5"- 21, e no m1 BY Ro er! A. Crowley ATTORNEY United States Patent 3,122,341 AUTGMA'IIC FLEET ANGLE COMPENSATION APIARATUS Franklin L. Le Bus, Sr., Reynold E. Smith, and Robert A.

Crowley, Longview, Tex., assignors to Le Bus Royalty Company, Lougview, Tex., a partnership Filed Dec. 8, 1961, Ser. No. 157,891 13 Claims. (Cl. 242-1571) This invention relates to improvements in cable spooling apparatus, and more particularly, but not by way of limitation, to a cable reeving automatic compensator apparatus particularly designed and constructed for compensating for and correcting the fleet angle of the cable when the fleet angle of the cable winding onto or off the drum is a detriment to the good even spooling of the cable so that it may be spooled on the drum efficiently and evenly without distortion or entangling of the cable during the winding operation. This application is a continuation-in-part of our co-pending application Serial Number 61,010, filed October 6, 1960, now Patent No. 3,083,932, and entitled Automatic Oscillating Angle and Off-Center Compensator Shaft and Floating Sheave Combination Apparatus.

Many problems are encountered in the winding or spooling of a wire line or cable onto a drum. Cable having a bad fleet angle from the stationary sheave to the drum core has a tendency to wind unevenly on the core of the drum, which results in a jerking and tangling of the cable as it is unspooled. This is a particular disadvantage in a hoisting or cable winding operation Wherein a relatively short mast is utilized with a relatively long spooling drum. Under this type of circumstance, the fleet angle of the cable between the fixed sheave and the drum is usually extremely excessive or bad, and it is often difficult to compensate for the angle to maintain a control of the spooling operation. In addition, it is important that each layer of the cable extend across the drum core from flange to flange with each successive wrap or turn of each layer of the cable being disposed in a close relationship to the adjacent wrap without piling up in the middle or either side of the drum core between the flanges. It is difficult to control the winding of the cable with the successive turns close together, particularly in well bore drilling operations wherein the load on the cable frequently causes a twisting of the cable. If the initial layer of the cable is inefficiently wound on the drum, and the fleet angle is bad, the error will be increased with each successive layer until the control of the cable will be substantially lost.

The spooling of multiple layers of cable onto the drum core has also presented a problem to the hoisting industry. A counterbalance spooling system for providing a true and eflicient Winding of multiple layers of cable has been developed by Franklin L. Le Bus, Sr., a coinventor of the present apparatus, and as disclosed in various Le Bus prior patents, such as United States Letters Patent No. 2,620,996, issued December 9, 1952, entitled Cable Winding Apparatus; No. 2,708,080, issued May 10, 1955, and entitled Hoisting Drum; No. 2,732,150, issued January 24, 1956, and entitled Balanced Cable spooling; and No. 2,734,695, issued February 14, 1956, and entitled Balanced Cable Spooling. The spooling system developed by the aforementioned patents has greatly advanced the cable spooling art and has met with wide acceptance in hoisting industry of all types. However, an eflicient control of the cable can be maintained with the counterbalanced spooling system only if the fleet angle of the cable between the fixed sheave and the drum is contained within certain limits, preferably not greater than approximately one and oneice half degrees, but not limited thereto. It has been found that a fleet angle in excess of this size, or greater than one and one-half degrees, creates further problems in the spooling operation in that the line will tend to be pulled up on a preceding wrap and start back on the next layer before the cables reaches the drum flange, or the cable will move two or three grooves toward the center of the drum as soon as it rises at the flange. In either event, there will be voids or gaps in the cable spooled on the drum, which results in an uneven winding on the core of the drum.

Many efforts have been made to improve the efficiency of cable winding operations, and many devices have been developed for guiding the cable or holding the line spooling onto the drum Within the necessary or desirable fleet angle limits. These devices are usually either expensive geared type structures, or are manually operated, with the inherent human errors and inefficiencies. in addition, the presently available reeving structures for this purpose normally provide a considerable amount of friction which must be overcome during the operation thereof, thus greatly reducing the efliciency of operation.

The present invention contemplates a novel fleet angle compensating apparatus providing for an automatic operation in accordance with the pressure or tension of the cable to maintain a smooth and even spooling operation. The friction in the operation of the novel compensating reeving device for eliminating fleet angle of the line as it is reeved onto the drum is reduced to a minimum for optimum efliciency of control of the cable during the winding thereof onto the drum. The fleet angle compensator is particularly designed to provide a compensation for the fleet angle in both vertical and horizontal planes. The cable passes over a fixed sheave and around a floating sheave whereby the tension or pressure in the cable causes the floating sheave to move in a curved path for maintaining the cable substantially perpendicular to the longitudinal axis of the spooling drum throughout the cable Winding operation.

The floating or movable sheave is interposed between the fixed sheave and the drum for receiving the cable therearound, and is carried by an eccentrically disposed shaft. The floating sheave is movable along the shaft in response to the pressure of the cable whereby the shaft is rocked or oscillated in an eccentric motion with respect to the axis of rotation thereof. As will hereinafter more fully appear, the axis of rotation of the shaft is non-coplanar with respect to the longitudinal axis of the shaft itself. The automatic eccentric movement of the shaft combined with the reciprocating lateral movement or shifting of the sheave therealong provides an arcuate path of motion for the center line of the sheave as the cable is wound or unwound from the drum. This arcuate reciprocation of the floating sheave maintains the length of the cable between the fixed sheave and the drum substantially constant throughout the spooling operation and compensates for the fleet angle between the fixed sheave and the drum. This action of maintaining the length of the cable constant between the fixed sheave and the drum is the important feature of the efficient compensation of the fleet angle, and results in a substantially perpendicular path for the cable with respect to the am's of the drum as the cable leaves the drum. This substantial elimination of the fleet angle results in a greatly increased efiiciency of the cable spooling operation. However, it is to be noted that the reeving apparatus or fleet angle compensator apparatus is not intended to be a cable spooling device in itself. The true and eflicient spooling provided by the aforementioned Le Bus counterbalanced spooling system is desirable to provide for the over-all efiicient results of the fleet angle compensator apparatus. The compensator apparatus will function to correct the fleet angle with substantially any cable spooling operation, but the end results of efliciently spooled cable on a drum will be only as true as the cable spooling device utilized therewith. Thus, it is important that the fleet angle compensator apparatus will be utilized with a counterbalanced spooling operation for optimum efiiciency thereof in cable winding in all hoisting operations.

It is an important object of this invention to provide a novel reeving apparatus for compensating for and controlling the fleet angle during the spooling of a line onto a drum in a true and accurate manner for substantially eliminating any distortion or entanglement of the cable during the spooling operation.

It is another object of this invention to provide a novel fleet angle compensator apparatus particularly designed and constructed for maintaining a substantially constant length for the cable between the fixed sheave and the drum throughout the spooling or unspooling operation.

Another object of this invention is to provide a novel fleet angle compensator apparatus which is responsive to the pressure of the cable for automatically compensating for the fleet angle in the cable spooling operation.

A further object of this invention is to provide a fleet angle compensator apparatus for automatically providing fleet angle compensation for both vertical and hori- Zontal movement of the cable.

Still another object of this invention is to provide a novel fleet angle compensator apparatus for automatically maintaining the cable substantially perpendicular to the axis of the drum at all times during a cable spooling operation.

A further object of this invention is to provide a fleet angle compensator apparatus wherein the eccentric shaft member thereof is journalled in a manner to provide for universal adjustment in accordance with variable field conditions.

A still further object of this invention is to provide a fleet angle compensator apparatus wherein the throw or eccentric movement thereof may be adjusted in accordance with variable field installations or change in the disposition of the fixed sheave with respect to the drum.

Another object of this invention is to provide a fleet angle compensator apparatus for automatically correcting a bad fleet angle and which is connected with the drum only through the cable itself.

Still another object of this invention is to provide a fleet angle compensator apparatus for automatically correcting a bad fleet angle which is responsive to the pressure in the cable for the operation thereof completely independent of manual or other attention.

A still further object of this invention is to provide a fleet angle compensator apparatus wherein the friction from a bad fleet angle during the operation thereof is reduced to a minimum for greatly increasing the efficiency thereof.

Other objects and advantages of the invention will be evident from the following detailed description, read in conjunction with the accompanying drawings, which illustrate our invention.

In the drawings:

FIGURE 1 is a perspective view of a fleet angle compensator apparatus embodying the invention and depicted in combination with a cable spooling drum and fixed sheave.

FIGURE 2 is a plan view of the fleet angle compensator apparatus depicted in FIG. 1.

FIGURE 3 is a sectional elevational view of the eccentric oscillation shaft of the invention.

FIGURE 4 is a perspective view of the eccentric shaft of the invention.

FIGURE 5 is a sectional view taken on line 5--5 of FIG. 3.

FIGURE 6 is a diagrammatic end View of the center line of rotation of the eccentric shaft.

4 FIGURE 7 is a force diagram of the forces acting on the eccentric shaft.

Referring to the drawings in detail, reference character a 10 generally indicates a drurn or winch having a cable l2 spooled thereon. The drum 10 may be journailed on a suitable shaft 14 for rotation, and is provided with opposed end flanges 16 and 18 as is well known. It is preferable that the drum 19 be provided with a core 29 (FIG. 2) having a plurality of cable receiving grooves 22 on the outer periphery thereof to facilitate the winding or spooling of the first layer or wrap of the cable 12 onto the drum It), as is well known in the industry, and as set forth in the Le Bus Counterbalance Spooling patents heretofore described. However, it is to be noted that any suitable drum or winch may be utilized with the invention.

A fleet angle compensator apparatus, generally indicated at 24, is secured in juxtaposition to the drum 10,

as will be hereinafter set forth, and is interposed be-' tween the drum 10 and a fixed position sheave 26. The cable 12 extends from the drum 10, through the reeving apparatus or fleet angle compensator apparatus 24,

around the sheave 25, and thence to the load (not shown) being manipulated thereby. The sheave 26 may be journalled for rotation on the shaft 27 in any well known manner (not shown), and is normally spaced from the drum as clearly shown in FIG. 1 in such a manner that the sheave 26 is substantially centrally disposed between the drum flanges 16 and 18. However, there are many installations in which the sheave 26 is disposed to either one side or the other with respect to the drum It and the fleet angle compensator apparatus 24 may be adjusted to correct for any mis-alignment or off-set installation of the sheave 26.

The fleet angle compensator apparatus 24 comprises a shaft 28 having end cap members 39 and 32 movably secured to the opposite ends thereof. The end caps 30 and 32 may be of any suitable type, and as depicted herein are substantially cylindrical and may be of a radially or diametrically split configuration (not shown) for facilitating the disposition thereof on the ends of the shaft 28. The inner periphery of each cap member 30 and 32 is preferably provided with an inwardly extending circumferential flange 34 (FIG. 3) for engagement with an annular groove 36 provided on each end of the shaft 28. The flanges 34 and grooves 36 cooperate for securely retaining the cap members 3%} and 32 against longitudinal movement with respect to the shaft 23 while permitting relative rotation of the cap members with respect thereto, as will be hereinafter set forth.

The end cap member 3!? is provided with an outwardly extending pivot arm 38 suitably journalled in a selfaligning bearing 39 whereby the axis of rotation 4% of the arm 38 is angularly disposed with respect to the axis of rotation 42 of the shaft 28. T he cap member 32 is similarly provided with an outwardly extending pivot arm 44 journalled in a suitable self-aligning bearing 45 whereby the axis of rotation 46 of the arm 44 is angularly disposed with respect to the axis of rotation 42 of the shaft 23. The arms 38 and 44- function as the pivot or rotational journals for the shaft 28. It will be apparent that the longitudinal axes of the journals 38 and 44 are not in alignment, but the inherent operation or action of the cooperating self-aligning bearings 39 and 45 will provide a common axis of rotation for the journals 38 and 44 throughout the spooling operation, as will be hereinafter set forth. The bearings 39 and 45 may be cairi d by suitable pillow blocks 48 and 59, respectively, which in turn may be supported on suitable brace members 52. The off-set and angular disposition which provides the eccentric rotation of the shaft 28, as described above, results from the fact that the longitudinal axis 42 of the shaft 28 (shown as line BC and BC' in FIGURES 6 and 7) and the common axis of rotation for the journals 3S and 44- (which is shown as A in FIGURE 6) are :lisp vsed in a skew or non-coplanar relation with respect to each other, as will clearly appear from a consideration of the drawings.

The end caps 39 and 32 are adjustable, or rotatable with respect to the shaft 2.8, as hereinbefore set forth, to permit orientation of the respective arms 38 and 44 in accordance with field installation conditions, as will be hereinafter set forth. Each cap 3t and 32 is provided with a radially extending threaded aperture 53 (FIG. 3) to receive a set screw (not shown) for engagement with the grooves 36 whereby the cap members may be secured in the desired relative orientation or position on the shaft 28. It is preferable to provide suitable indicia or indications 54 (FIGS. 4 and 5) on the inwardly disposed faces of the caps 35) and 32 in order to facilitate the determination of the angular disposition or spacing between the journals or pivot arms 38 and 44.

The distance between the center line of the arm 44 and the center line of the shaft 28 is known as the throw of the arm 44, as clearly indicated in FIG. 5, and similarly, the distance between the center line of the arm 33 and the center line of the shaft 28 is known as the throw of the arm 38. Thus, the angular disposition between the arms 33 and 44- is the angle between the throws thereof. The end caps 30 and 32 may be manually rotatively adjusted with respect to the shaft 28 in order to provide the desired angular distance between the throws of the arms 33 and 44 in accordance with the particular field installation with which the fleet angle compensating device 24 is to be utilized. Of course, the angular indications or indicia 54 imprinted or otherwise provided on the end caps 31 and 32 provide for a visual determination of the selected angular disposition of the throws. It will be apparent that one of the end caps may be stationary and the other rotatable, if desired, and in this instance, the movable end cap will be manually rotated for proper orientation between the pivot arms 38 and 44. f course, in any event, the rotatable end caps may be securely retained in the selected position by the cooperation between the aforementioned set screws (not shown) and the respective groove 36.

A floating sheave or pulley 56 is journalled on the shaft 28 and is movable therealong in response to the tension or pressure on the cable 12 being spooled or unspooled from the drum it The sheave 56 may be journalled on the shaft 28 in any suitable manner, such as generally depicted in P16. 3. As shown therein, a bearing sleeve or bushing member 58 is secured around the shaft 28 in any suitable manner and is rotatable thereon as well as movable therealong. The sheave or pulley 56 is provided with a central hub portion 60 adapted for disposition around the bushing 58 and secured thereon in any suitable manner, such as keyed thereto, or the like, but not limited thereto. The pulley 56 is thus secured to the bushing 58 whereby the bushing and pulley or sheave s will rotate and move along the shaft 28 as a unit.

A pair of spaced set collars 62 and 6 may be provided on the shaft 28, as shown in FIG. 3, for limiting the longitudinal movement of the sheave S6 therealong. The collars 62 and 64 are slidably disposed on the shaft 28 and may be manually moved therealong to the desired position therefor in accordance with the optimum spacing therebetween most desirable for the field installation. Each collar 62 and 64 is preferably provided with at least one radial extending threaded aperture 66 for receiving a set screw (not shown) in order to securely lock the collars 62 and 64 in the pre-selected position on the shaft 23. It will be readily apparent that engagement of the moving sheave 56 with the collar 62 will limit the movement of the sheave in a left hand direction, as viewed in FIG. 3, and engagement of the sheave 56 with the collar 64 will limit the movement of the sheave in a right hand direction.

As hereinbefore set forth, the throw of the shaft 28 may be defined as the distance between the axis of the shaft and the axis of the respective arms 38 and 44, and the angle between the throws may be varied in accordance with the drum and sheave installation or operating conditions by independent rotation of at least one of end caps 3t and 32. The angle between the throws is indicated by the angle BAC in FIG. 6, and is preferably maintained at an angle less than one hundred eighty degrees. It has been found under practical working conditions that when the angle BAC approaches or becomes as great as one hundred eighty degrees, the apparatus 24 .i ay not operate automatically with the usual efliciency possible when the angle BAC is less than one hundred eightly degrees. In addition, the length of the throw may be varied in accordance with the operating conditions to provide the most eflicient eccentric movement for the shaft 28 for compensating for and correcting the fleet angle of the cable 12, as will be hereinafter set forth.

The axis of rotation of the shaft 28 is the common rotational axis between the journals 38 and 44 as maintained by the self-aligning bearings 39 and 45. Of course, the angular disposition between the rotational axis of the shaft 28 and the longitudinal axis of the shaft results in an eccentric movement or eccentric oscillation for the shaft during the spooling operation. The eccentric oscillation of the shaft 28 transmits an arcuate movement to the sheave 56 journalled thereon whereby the center line of the sheave 5s moves through an arcuate path as the cable 12 is spooled onto or unspooled from the drum This movement of the floating sheave 56 through an arcuate path causes the over-all length of the cable 12 between the fixed sheave 26 and the drum 10 to remain substantially constant throughout the spooling operation.

It will be apparent that retaining nuts 69 and 71 may be provided on the outer extremities of the arms 38 and 44 for retaining the arms in the respective bearings. In addition, it is desirable to provide an indexing line in alignment with a second indexing line 181 011 the outer periphery of the shaft 28, and in the proximity of the end caps 32 and 36, respectively. In this manner, the angular adjustment between the arm members 38 and 44 may be determined by the cooperating index lines 100 and 181 and the indications 54.

\ Operation The fleet angle of the cable 12 is the angle at the fixed sheave between the actual path of the cable and an imaginary line extending perpendicularly between the fixed sheave 26 and the axis of the drum 19. In spooling operations wherein no fleet angle compensator device is utilized in cooperation with the spooling drum, the cable or line 1.2 will tend to seek the shortest distance from the fixed sheave 2% to the drum. In other words, the line 12 will try to pile up at a point on the drum where a line passing through the sheave 26 is perpendicular to the drum axis. It will be apparent that if the length of the cable 12 between the sheave 26 and the drum 19 is maintained substantially constant at all times during the spooling operation of each wrap of every layer, there will be no shortest distance for the cable to seek. As a result, there will be no preferred position on the drum where the cable will tend to pile up. Thus, the fleet angle compensator apparatus 24 is interposed between the fixed sheave 26 and the drum 1% to maintain the length of the cable 12 therebetween substantially constant on each separate layer throu hout the spoolin g operation.

The floating sheave 56 moves laterally along the shaft 28 in response to the pressure or tension in the cable 12 during the spooling or unspooling thereof from the drum it). Any movement of the cable to the left or right of the mean or center point of the drum 19 will cause the compensating or floating pulley 56 to move to either the left or right of the center point in accordance with the direction of the spooling, or unspooling of the line or cable. The pressure of the cable 12 and the sheave 56 oscillates the shaft 28 about the axis of movement of the journals 38 and 44 for changing the angular position of the shaft, as clearly shown in FIG. 2. Suitable stop means (not shown) may be provided for limiting the oscillation of the shaft 28 in both the clockwise and counter-clockwise directions whereby the shaft rocks or oscillates about the axis of movement in accordance with the direction of travel of the cable 12. As a result, the center line of the sheave 56 moves through an arcuate path, as indicated by the dotted line D in FIGS. 2 and 3.

The oscillating movement of the shaft 23 moves the sheave 56 alternately toward and away from the drum 1% whereby the cable segment between the drum and the floating sheave 56 is alternately shortened and lengthened with a corresponding lengthening and shortening of the cable segment between the fixed sheave 26 and the floating sheave 56. This maintains the over-all length of the cable 12 between the fixed sheave 26 and the drum substantially constant at all times during the winding or unwinding of each separate layer of line wraps, and as a result, the cable 12 moving from or to the drum 19 from the sheave 56 remains substantially perpendicular to the longitudinal axis of the drum, thus eliminating the fleet angle, and the inherent disadvantages thereof.

The friction contact of the cable being wound on the drum exerts a pressure through the cable which is transmitted to one side of the sheave 56, thus causing the sheave 56 to move in the direction in which the pressure is exerted. Since the sheave 56 is transversely movable on the shaft 28, the sheave will follow the pressure and move along the shaft 28 in accordance with the Winding of the cable on the drum, or unwinding thereof, as desired. Therefore, if the cable 12 moves in a left hand direction, as viewed in FIGS. 1 and 2, toward the drum flange 16, the sheave 56 will move along the shaft 28 in a left hand direction due to the pressure of the cable acting against the flange 70 of the sheave. This movement of the sheave 56 oscillates the shaft 28 in a direction for moving the end cap 3!! toward the drum 10, thereby shortening the cable segment between the drum and the sheave 56 and simultaneously lengthening the cable segment between the floating sheave 56 and the fixed sheave 26.

Similarly, when the cable is moving in a right hand direction, or toward the drum flange 18 (the right hand disposition of the sheave is not shown in the drawings), the pressure of the cable acting against the flange portion 72 of the sheave 56 moves the sheave in a right hand direction for oscillating the shaft 28 in a direction for moving the end cap 32 toward the drum 1! It will be apparent that the rocking motion of the shaft 28 is continual as the sheave 56 moves laterally or longitudinally therealong, thus constantly compensating for and correcting the fleet angle and maintaining the cable substantially perpendicular to the axis of the drum at all times during the spooling operation.

As shown diagrammatically in FIG. 6, points B and C represent the ends of the center line or axis 42 of the shaft 28. The angle BAC is the angle between the throws, and the distance or length BA and CA each represent the length of the throws. The line of pull of the cable always passes through the bearing journals at A. As the sheave 56 moves along the line BC, which represents the axis of the shaft 28, and toward the point C, the angle BAC shifts to the position indicated in dotted lines as B'AC'. In doing this, it can be readily seen that the sheave 56 has moved in the direction of the line of pull by the distance indicated at X (also shown in FIG. 2). It is this movement of the sheave 55 that maintains the length of the cable or line 12 from the drum It? to the fixed sheave 26 constant at all times on each separate layer of line wraps.

FIGURE 7 is a force diagram of the forces acting on the shaft 28. Points B and C represent the ends of the axis 42 of the shaft 28. This view is closely related to 8 7 that shown in FIG. 6. When the shaft 28, indicated by the line BC, is not moving, it will be apparent that the summation of moments about the point P, which is the point of pull of the cable on the shaft 28, will be equal to zero. In other words, the force C' times the moment arm M minus the force B times the moment arm N equals zero. The only external forces on the shaft 28 result from the pressure or tension of cable 12. As the sheave 56 moves toward C, for example, the force at C becomes greater, but the moment arm M simultaneously becomes shorter, and conversely, the force at B becomes less but the moment arm N becomes longer. Therefore, throughout the entire spooling operation, the shaft 28 and sheave 56 remain in a state of equilibrium.

As hereinbefore set forth, the angle BAC between the throws can be adjusted in accordance with the particular field installation with which the apparatus 24 is to be utilized in order to provide optimum efliciency. The end caps 30 and 32 may be manually rotated with respect to the shaft 28 for setting the respective journals 38 and 44 at the desired angular disposition, whereupon the caps may be locked securely to the shaft. The self-aligning bearings 39 and 45 compensate for the angular adjustment of the arms 38 and 44' and maintain a common oscillating axis therebetween. In addition, the set collars 62 and 64 may be secured to the shaft 28 and spaced in order to limit the lateral or longitudinal travel of the sheave 56 on the shaft 28 in accordance with the particular installation problems. It is preferable to position the set collars 62 and 64 on the shaft 28 in such a manner that the cable does not quite reach a full ninety degree angle with respect to the drum axis when the sheave 56 approaches the drum flange. This creates a slight fleet angle in the cable at the vicinity of the drum flange and the cable will then automatically rise to the next layer and proceed back across the drum. If the cable is permitted to reach the full ninety degree position with respect to the drum axis at the end of a layer, the line or cable has a tendency to pile up at the flanges, which is a disadvantage as hereinbefore set forth.

By way of summary, the fleet angle correction apparatus 24 automatically compensates for and corrects the fleet angle of the cable coming from the fixed position sheave 26 and maintains the cable in a substantially perpendicular relationship with regard to the axis of the drum 10 during the spooling or unspooling operation. The pressure of the cable passing under the floating sheave 56 automatically causes an oscillating or rocking movement of the shaft 28 simultaneously with a transverse movement of the sheave 56 therealong for maintaining a constant length (for the cable between the fixed sheave and the drum during the spooling of each separate layer. Thus, the true and even spooling of the cable onto the drum by means of a counterbalanced spooling system, such as disclosed in the prior Franklin L. Le Bus, Sr. patents, can be greatly facilitated and improved in hoisting or spooling operations wherein the fleet angle is excessive or detrimental to the efliciency of the winding operation.

From the foregoing, it will be apparent that the present invention provides a novel reeving apparatus for compensating for and correcting the fleet angle in the spooling or unspooling of a line from a winch or drum for effecting an eflicient :winding of the line onto the drum without any distortion or entanglement thereof. The novel reeving apparatus is automatically shifted or oscillated by the pressure of the cable or line being spooled for maintaining the line substantially perpendicular to the axis of the drum throughout the spooling operation. The off center shaft may be so designed and constructed to automatically provide for the optimum oscillation or rocking movement thereof in accordance with the installation of the hoisting equipment. The novel fleet angle compensator apparatus is simple and eflicient in operation and economical and durable in construction.

Changes may be made in the combination and arrangement of parts as heretofore set forth in the specification and shown in the drawings, it being understood that any modification in the precise embodiment of the invention may be made within the scope of the following claims without departing from the spirit of the invention.

We claim:

1. In combination with a drum having a cable wound thereon, a fleet angle compensator apparatus comprising an off center disposed shaft, a movable sheave journalled on the shaft for receiving the cable, means carried by the shaft to provide for oscillation thereof about an axis off-set from and non-coplanar with respect to the normal axis of the shaft, said sheave slidably secured to the shaft and movable therealong in response to pressure of the cable for oscillation of the shaft on the axis of limited rotation for maintaining the cable substantially perpendicular with respect to the axis of the drum, and means for automatically adjusting the o-i-set axis of oscillation for the shaft in accordance with variable cable spooling conditions.

2. In combination with a dnlm having a cable wound thereon, a fleet angle compensator apparatus comprising an off center shaft, offset journal means carried by the shaft to provide an axis of oscillation thereof angularly disposed and non-coplanar with respect to the axis of the shaft, self-aligning means cooperating with the oif-set journal means for automatically adjusting the axis of oscillation in accordance with variable cable spooling conditions, a sheave journalled on the shaft for receiving the cable and slidably secured thereon for movement therealong in response to the pressure of the cable for oscillating the shaft about the axis of limited rotation, said oscillation of said shaft cooperating with said movement of said sheave along the shaft to provide an arcuate path of movement for the center line of the sheave for maintaining the cable substantially perpendicular to the axis of the drum.

3. A fleet angle compensator for a cable drum spooling apparatus comprising a shaft, a pair of cap members movably secured at each end of the shaft, journal means carried by the cap members, self-aligning means supporting the journal means for oscillation thereof on a common axis of limited rotation, said axis of rotation disposed at an angle with respect to the axis of the shaft to provide an eccentric movement of the shaft upon rotation thereof, means cooperating between the cap members and the shaft for adjusting the angular disposition between the throws of the journal means in accordance with variable spooling conditions, a sheave journalled on the shaft and slidably secured thereon for movement therealong, said sheave interposed between the drum and a fixed position sheave having the cable extending therebetween, said first mentioned sheave movable along the shaft in response to pressure of the cable for rocking the shaft to provide an arcuate path of motion for the center line of the movable sheave whereby the cable is maintained substantially perpendicular to the axis of the drum.

4. In combination with a drum having a cable wound thereon, a fleet angle compensating apparatus comprising an off center shaft, a movable sheave journalled on the shaft for receiving the cable therearound, means to provide an off-set axis of oscillation for the shaft, said axis of oscillation being non-coplanar with the axis of the shaft, means for adjusting the disposition of the off-set axis in accordance with variable cable spooling operations, self-aligning means for automatically adjusting the off-set axis during the cable spooling operation, said sheave slidably secured to the shaft for movement therealong in response to the pressure of the cable for oscillating the shaft in an eccentric movement whereby the center line of the sheave moves in an arcuate path for maintaining the cable substantially perpendicular to the axis of the drum.

5. A fleet angle compensator for use with a cable drum spooling apparatus receiving the cable from a fixed sheave and comprising a shaft, a pair of adjustable cap members disposed at each end of the shaft, an off-set pivot arm carried by each cap member, self-aligning means supporting each pivot arm to provide for limited rotation thereof about a common axis, said common axis disposed at an angle and off-set and non-coplanar with respect to the axis of the shaft to provide for an eccentric movement of the shaft upon rotation thereof, a sheave journalled on the shaft and slidably secured thereto for movement therealong said sheave interposed between the drum and the fixed position sheave having the cable extending therebetween, said slidable sheave movable along the shaft in response to pressure of the cable for rocking the shaft to provide an arcuate path of motion for the center line of the sheave whereby the cable is maintained substan tially perpendicular to the axis of the drum, and means limiting the movement of the sheave along the shaft in alternate directions for facilitating the reversal of the cable at the end of each layer being spooled onto or unspooled from the drum.

6. In combination with a drum having a cable wound thereon, a fleet angle compensating apparatus compris ing an off set shaft, a movable sheave journalled on the shaft for receiving the cable therearound, adjustable means carried by the shaft to provide an off-set axis of limited rotation therefor, said off-set axis of rotation being non-coplanar with the axis of the shaft, said sheave slidably secured to the shaft for movement therealong in response to the pressure of the cable for oscillating the shaft in an eccentric movement whereby the center line of the sheave moves in an arcuate path for maintaining the cable substantially perpendicular to the axis of the drum, and means carried by the shaft for limiting the movement of the sheave therealong in opposed directions for facilitating the reversal of the cable at the end of each layer being wound onto the drum.

7. In a fleet angle compensator apparatus for cable spooling, a shaft, cap members movably secured at the opposed ends of the shaft, off-set journal means carried by each cap member, self-aligning means supporting the journal means to provide a common axis of limited rotation therefor, said axis of rotation being non-coplanar with respect to the longitudinal axis of the shaft, said angular disposition of said axis of rotation providing an eccentric movement for the shaft upon rotation thereof.

8. In a fieet angle compensator apparatus for cable spooling, a shaft, cap members movably secured at the opposed ends of the shaft, off-set journal means carried by each cap member, means for adjusting the angle between the throws of the journal means, self-aligning means supporting the journal means to provide a common axis of rotation therefor, said axis of rotation off-set and angularly disposed with respect to the axis of the shaft to provide an oscillating movement for the shaft upon rotation thereof.

9. In a fleet angle cable compensator apparatus, a shaft, off-set arm members movably secured to each end of the shaft, means for adjusting the relative angular disposition of the arm members, self-aligning means supporting the arm members to provide a common axis of rotation thereof off-set from and angularly disposed with respect to the axis of the shaft to provide an eccentric oscillating movement for the shaft, 2. sheave journalled on the shaft and interposed between a drum and a fixed sheave having a cable extending therebetween, said sheave slidably disposed on the shaft for movement therealong for oscillating the shaft about the off-set axis of rotation to maintain the cable substantially perpendicular to the axis of the drum.

10. A line fleet angle compensator apparatus comprising a shaft, journal means carried by the shaft and providing an angularly disposed and off-set axis of rotation for the shaft, means for adjusting the relative angular position of the throws of the journal means, a sheave jour- 1 l nailed on the shaft and slidably secured thereto for movement therealong, said shaft rotatable in an oscillating movement in response to the movement of the sheave therealong.

11. A line fleet angle compensator apparatus comprising a shaft, journal means carried by the shaft and providing an angularly disposed and oiT-set axis of rotation for the shaft, means for adjusting the relative angular position of the throws of the journal means, self-aligning means supporting the journal means for constantly adjusting the off-set axis during a line spooling operation, a sheave journalled on the shaft and slicla-bly secured thereto for movement therealong, said shaft rotatable in an oscillating movement in response to the movement of the sheave therealong.

12. In combination With a drum having a cable Wound thereon, a fleet angle compensator apparatus comprising an eccentrically disposed shaft, a movable sheave journalled on the shaft and slidably secured thereon for receiving the cable, and adjustable journal means carried by 20 the shaft for varying the angle between the throws of the journal mean in accordance with cable spooling conditions.

13. In combination With a drum having a cable Wound thereon, a fleet angle compensator apparatus comprising an eccentrically disposed shaft, a movable sheave journalled on the shaft and slidably secured thereon for receiving the cable, adjustable means carried by the shaft to provide for rotation thereof about an axis ofi-set from and non-coplanar with respect to the normal axis of the shaft, self-aligning means supporting said adjustable means, said sheave movable along the shaft in response to pressure of the cable for oscillation of the shaft about the axis of rotation for maintaining the cable substan tially perpendicular to the axis of re drum, and means carried by the shaft for limiting the movement of the sheave therealong in opposite directions for facilitating the reversal of the cable at the end of each layer during the cable Winding operation.

References Cited in the file of this patent UNITED STATES PATENTS 941,722 Moulton Nov. 30, 1909 2,228,346 Downie Ian. 1 1941 2,738,938 Benson et al. Mar. 20, 1956 2,922,599 Bigelow Jan. 26, 1960 

1. IN COMBINATION WITH A DRUM HAVING A CABLE WOUND THEREON, A FLEET ANGLE COMPENSATOR APPARATUS COMPRISING AN OFF CENTER DISPOSED SHAFT, A MOVABLE SHEAVE JOURNALLED ON THE SHAFT FOR RECEIVING THE CABLE, MEANS CARRIED BY THE SHAFT TO PROVIDE FOR OSCILLATION THEREOF ABOUT AN AXIS OFF-SET FROM AND NON-COPLANAR WITH RESPECT TO THE NORMAL AXIS OF THE SHAFT, SAID SHEAVE SLIDABLY SECURED TO THE SHAFT AND MOVABLE THEREALONG IN RESPONSE TO PRESSURE OF THE CABLE FOR OSCILLATION OF THE SHAFT ON THE AXIS OF LIMITED ROTATION FOR MAINTAINING THE CABLE SUBSTANTIALLY PERPENDICULAR WITH RESPECT TO THE AXIS OF THE DRUM, AND MEANS FOR AUTOMATICALLY ADJUSTING THE OFF-SET AXIS OF OSCILLATION FOR THE SHAFT IN ACCORDANCE WITH VARIABLE CABLE SPOOLING CONDITIONS. 